Computer-aided image processing and analysis has become an important technology for the analysis of biological structure. Ten principal investigators in the Department of Anatomy, Division of Neuroscience at The University of Tennessee Center for the Health Sciences are requesting a MAGISCAN 2A Image Analyzer and ancillary equipment to process and analyze histological materials. The proposed instrumentation includes video input from newvicon and silicon intensified target (SIT) cameras; image digitizing, memory, and storage hardware; monochrome and color display monitors provided with the MAGISCAN; and a Nikon microphot microscope with epifluorescence and related equipment for data input. The instrument will be used for the following research projects: 1.) Semi-automated reconstruction of intracellularly stained neurons; (2.) measurement of particle sizes and densities and cluster analysis in freeze fracture replicas; (3.) analysis of one and two-dimensional electrophoresis gels; (4.) densitometric measurement of fluorescent strained tissues; (5.) measurement of labeling intensities and plots of the spatial distributions of immunocytochemically tagged cells, fibers, and membranes or organelles; (6.) autoradiographic grain counting and densitometric measurements of radiolabelled transmitter ligands and receptor site studies. Software is already available on the MAGISCAN 2A for many of these proposed applications. The modular structure and menu-based software of this turnkey system will minimize additional development costs. Space, a half-time programmer, and maintenance and operating costs will be provided by the Department of Anatomy.